ARMY TM 5-5420-212-10-1 MARINE CORPS TM 08676A-10/1-1 3-17 DOUBLE STORY 2E+13 thru 2E+22 BAY DESIGN WITH LRS The  procedures  that  follow  are  for  design  of  DS  2E  +  13  through  2E  +  22  bay  MGBs  (w/LRS)  on  normal  sites where water level or any obstructions are at least 3.7 m below bank heights: a. Measure the AR gap (para. 3-10a) b. Select a bridge (para. 3-10b and Table 3-31) Table 3-31. DS MGB Design13-22 Bays with LRS Site and Bridge Dimensions AR GAP RANGES (a) MLC* (b) 2E + No. of Bays (c) Bridge Length L (d) R Distance (e) Nose Const (f) 28.3-30.9 70(T) 13 32.9 27.7 7N1 30.2-32.8 70(T) 14 34.8 29.0 7N1 32.0-34.1 70(T) 15 36.6 29.0 7N1 33.8-36.4 70(T) 16 38.4 29.6 8N1 35.6-38.2 70(T) 17 40.2 29.6 8N1 37.5-40.1 70(T) 18 42.1 29.6 6N1+3N2 39.3-41.9 70(T) 19 43.9 35.1 6N1+3N2 41.1-43.7 70(T) 20 45.7 38.7 6N1+3N2 43.0-45.1 70(T) 21 47.6 38.7 6N1+3N2 44.8-46.2 70(T) 22 49.4 40.5 6N1+3N2 * See step k. Slope Check and Table 1-1 for crossing restrictions and MLC 100(W) capability. (T) = Tracked c. Bridge Length Read and note the number of bays and bridge length, Table 3-31 columns (c) and (d). d. R Distance Read and note the R distance, Table 3-31 column (e). e. Nose Construction Read and note the nose configuration, Table 3-31 column (f). f. Key Construction Points Identify,  locate  and  take  elevations  at  the  key  construction  points.  These  construction  points  are  explained  below  and shown in Figure 3-15. (1) F  peg-Designates  the  location  of  the  far  bank  end  of  bridge  (outer  edge  of  bankseat  beam).  Initially placed distance given as minimum bearing in Table 3-32 for the bridge being designed. The distance, between the A and F peg is the amount of bridge that will bear on the far bank, and is known as the far bank bearing. 3-42